xdy/dx-2y+x=0
dy/dx-2y/x+1=0
设y/x=u
则xdu/dx+u-2u+1=0
du/(u-1)=dx/x
两边积分得∫du/(u-1)=∫dx/x
即ln(u-1)=lnx+C1
u-1=Cx
y/x-1=Cx
y=Cx²+x